nicohvc: The score shouts "I'm a Sierra game" but is located at the right of the screen. When its there is between brackets (Sorry for my english if that's the wrong word)
Well the only exception that I've know are games like eco quest where the background colour change.

Maybe it's a fanmade game which honors the classics sierra "quest" series ?

Stair Quest? Yeah that's the game. Last night I thought that it was a fan/indie... well, with your clue (less stairs) it was more easy to find it :)

It was a hardcore. I've watched the entire Sierra point and click catalogue last night xD

nicohvc: also here on gog

Ghorpm: Lilly Looking Through

Ghorpm: Next

Nightblair: Entomorph: Plague of the Darkfall. My favourite from childhood, although I could not understand what it was about back then, as my English skill was not on par. Nevertheless, trips into the ant nests was unforgettable.

Nightblair: Hereby my drawing skills.

Austrobogulator: I think you might be looking for this thread.

Nightblair: Here is the image from game then.

Nightblair: I'm sorry, I've never noticed there are two threads of this game. Here is the image from game then.

Densetsu: The creature is called lurker; it is from what I objectively consider the best game of all time, Ultima Underworld: The Stygian Abyss.

Nice drawing of it too. :)